Optical elements, such as optical lenses or light guide plates used in electronic devices, are easily manufactured using an injection molding die. During the manufacturing of an optical element, an original product, which includes a stub bar and an optical element, are first molded using the injection molding die. Then, the original product is cut to separate the optical element from the stub bar using a cutter, such as a trimming pliers or scissors. However, the mechanical cutting between the cutter and the original product often generates internal stress, which may make cracks appear on the optical element. Furthermore, the cutter becomes dull after a long time of use, which make burrs form at the edges of the optical element.
Therefore, it is desirable to provide a laser cutting device and a laser cutting method using the laser cutting device, to overcome or at least alleviate the above-mentioned problems.